/Engine/Source/Runtime/Core/Public/Misc/FileHelper.h
note this also calls SendDataToPCViaUnrealConsole and uses GenerateNextBitmapFilename if Pattern does not have ".bmp" on it
true if success
static bool CreateBitmap ( const TCHAR * Pattern, int32 DataWidth, int32 DataHeight, const struct [FColor](API\Runtime\Core\Math\FColor) * Data, FIntRect * SubRectangle, [IFileManager](API\Runtime\Core\HAL\IFileManager) * FileManager, [FString](API\Runtime\Core\Containers\FString) * OutFilename, bool bInWriteAlpha, [EColorChannel](API\Runtime\Core\Misc\FFileHelper\EColorChannel) ColorChannel )